[Elecraft] K3 + LP100A + Dummy Load

[n5ge at n5ge.com]

Phil,

You don't say what type of dummy load you are using, but all of the cantenna
type have about the same SWR curve you witnessed.  You will need a precision DL
to get a flat response across a large range.  I have two DECIBEL DB4304B 100
watt loads here that are flat up through 2m.  I don't think they are made any
more and if they were they would be very expensive.  The two I have were bought
at a ham hamfest for $50 each.  They are bout 6" x 4" x 4" Most of which is
cooling fins.

Be careful when you buy dummy loads like this at a Hamfest. Take a good
ohm-meter with you.  I bought a couple of really well made heavy duty DL's that
were rated at 300w for $100 once and when I measured them at home they were 75
ohm loads, so watch out!

Happy holidays,

73,
Tom
Amateur Radio Operator N5GE
ARRL Lifetime Member
QCWA Lifetime Member

"If somebody has a bad heart, they can plug this jack in at 
night as they go to bed and it will monitor their heart 
throughout the night. And the next morning, when they wake up 
dead, there'll be a record."

--Mark S. Fowler, FCC Chairman,
  1981 - 1987


On Thu, 22 Dec 2011 08:37:37 -0800, Phil Hystad <phystad at mac.com> wrote:

>Is this normal or can someone explain?  I was looking at the R+iX values reported by the LP100A with my K3 feeding a dummy load.  The SWR reported was always small but never super close to 1:1.  Most of the SWR in this setup was 1.1:1 up to 1.5:1.  The R values ranged from 34 ohms to up to 59 ohms and X was ranging over a number of smallish values < 20 for all the bands.
>
>Is this what most of you would call normal?
>
>Does the K3 output R+iX vary from band to band (I assume so) and is that what I am seeing?
>
>I had thought my dummy load was mostly frequency independent so I am not sure if I am seeing mostly the K3 here or maybe the K3 plus the 6 feet of coax (RG8X) + dummy load.
>
>73, phil, K7PEH
>